Do not believe a thing because many people speak of it

At least not in the modern sense. A republic is now defined as a government of officials elected by the people to represent the interests of said people in running the country. While Rome’s republic was similar to this, it was, at its corrupt and dark heart, an oligarchy (ruled by a small group of people: the aristocrats, or patricians). The common Roman citizen had a vote, but it did not count as much as that of a rich man’s when electing Rome’s officials for office.

The Roman Republic was (and shall always be) called a republic because it comes from the Latin re publica, or “the public thing.” The adjective publica is an easy cognate for our word “public,” whereas the less obvious re gives us rebus, and the ubiquitous Re: in emails, which in Latin is about this thing…